Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6
Renewable Energy Based Hybrid Nano-Power Station for Remote Isolated Island Imran Khan1, P. K. Halder1,*, N. Paul2 In this paper a nano power station scheme is proposed for the remote isolated island. Here we considered Saint Martin, an isolated island in Bangladesh for this design consideration. Renewable solar and wind energy sources are used in this proposed nano power station for better sustainability. Though the electricity demand in this island is 3.1 MW/day, we are proposing a 100 KW nano power station to support the basic electricity need. Considering 120 watt basic power consumption per family the total power requirement is 93.36 KW and our proposed system capacity is 100 KW. The annual solar irradiation and average wind speed in 2 this island are 4.86 kWh/m /day and 4.89 m/s respectively which is sufficient for the proposed renewable energy based nano-power station.
Key wards: Renewable Energy; Solar Energy; Solar Intensity; Wind Energy; Wind Speed; Hybrid Nano Power Station.
Field of Research: Energy 1. Introduction Bangladesh-one of the most densely populated country in the world facing daunting energy crisis. The country has a population about 160 million at the end of 2012 and a total area of 144,000 sq. km comprises of 133,910 sq. km land and 10,090 sq. km water. Only about 49% of total population has access to use electricity yet, though the Government of Bangladesh has announced its vision to provide electricity for all by the year 2020. Over 85% of the population lives in rural, remote, coastal and isolated areas in Bangladesh. However, it is matter of regret that, only 10% of them have the electricity facility (BPDB 2013). The energy crisis is becoming the main problem to mankind facing today due to rapid depletion of non-renewable energy resources like fossil fuels, oils and natural gases (Halder et al. 2012). Thus this rapid diminishing of the known reserves of commercial primary energy sources in Bangladesh forces to find renewable energy sources (Islam 2001). Bangladesh has location between 20°34' and 26°38' north latitudes and 88°01' and 92°41' east longitudes and the coastal area in the southern part has a huge potential of establishing solar and wind power generation. The country has an average daily solar radiation of 4 – 6.5 kWh/m2 and an average wind speed of 3 - 9 m/s at different height (http://en.wikipedia.org/wiki/Wind_power). As the grid expansion is very expensive to isolated coastal areas (Saint Martin, Kutubdia) thus, attempts have been taken to popularize the use of renewable energy sources.
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Imran Khan , Jessore Science & Technology University, Jessore-7408, Bangladesh. 1 P. K. Halder , Jessore Science & Technology University, Jessore-7408, Bangladesh. *E-mail:
[email protected], 2 N. Paul , Bangladesh University of Engineering & Technology, Dhaka-1000, Bangladesh
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Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 The annual average wind speed in Saint Martin is 6.74 m/s at 50m height and the solar irradiation is 4.85kWh/m2/day which are suitable to harness both wind energy and solar energy. Thus, an off-grid solar-wind hybrid energy system can be installed to meet energy demand which can help to improve load factors and assist on replacement costs as it can harmonize each other (Ashok 2007, Kaldellis et al. 2006). This paper outlines different system components of hybrid energy system and presents a design of off-grid solar-wind-hybrid power system for Saint Martin of Bangladesh.
2. Present Energy Scenario in Bangladesh Electricity is a pre-requisite for the technological development and economic growth and plays a pivotal role to attain Millennium Development Goals (MDGs) of a nation. Bangladesh is energy starve country and has been facing a severe power crisis for about a decade due to increasing power demand. Besides, Bangladesh is a low income country with a very low Gross Domestic Product (GDP), though GDP per capita is increasing (7.98%) significantly in the year 2000 2010. A field survey shows that GDP growth rate (%) 4.4% in 2002, 5.3% in 2003, 4.9% in 2004, 6.4% in 2005, 6.6% in 2006, 6.3% in 2007, 4.9% in 2008 and 5.4% in 2009. Table 1 shows the present power scenario in Bangladesh (Haque 2011).
Sector
Table 1: Power Scenario in Bangladesh, 2011 Status
Electricity Growth
10% in FY 2010 (Av. 7% since1990)
Total Consumer
12 Million
Transmission Line
8,500 km
Distribution Line Distribution Loss Per capita Generation
2,70,000 km 13.1% 236 kWh
Access to Electricity
48.5%
Present Generation Capacity
5936 MW
Present Demand
6000 MW
Present Available Generation
4000-4600 MW
Recent Maximum Generation
4699 MW ( August 2010)
Electricity generation in Bangladesh is largely depends on indigenous fuel i.e. natural gas and coal and natural accounts about 76% of electricity generation. Bangladesh relies greatly on fossil fuels for its energy, but the present reserve would be depleted by the year of 2015 (Bangladesh Energy Crisis 2011). At present the power demand in Bangladesh is about 6000MW, whereas the generation capacity is 5936MW (Haque 2011). Currently, consumers cannot be provided with uninterrupted and quality supply of electricity due to this inadequate generation compared to the national demand. A recent survey shows that the country faces 1100 MW load shading during the fiscal year 2010-2011 as shown in Figure 1(BPDB 2013, A publication of Spilling Energy System 2008).
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Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 Figure 1: Power crisis in Bangladesh.
3. Solar Energy Resources in Saint Martin Saint Martin Island is the most beautiful island of Bangladesh which is located at the southern bay and 48 km from Teknaf with an area of only 8 sq. km. Local name of the island is "Narkel Jinjira" which means island of coconut. The Island has a total population of 7000 with a density of 875 per sq. km. However, the Island is suffering from acute power crisis due to unavailability of grid power. The people satisfy their lighting need by expensive and often erratic supply of kerosene. There are approximately 778 families in the island and normally they use light, fan, TV and other small loads. Considering same load demand of all the houses, the estimated total electrical load demand for the island is 3.1 MW/day (A Pre-Feasibility Study Report 2010) as shown in Figure 2. Figure 2: Average demand of load for houses of Saint Martin
Due to the remoteness and inadequate infrastructure for transport sector, there is no grid power plant. Thus, renewable energy can be an effective way to meet the power demand of this Island. The location of the Island, 20°37'45.64"N and 92°19'29.00"E is suitable for harnessing solar energy (http://icwow.blogspot.com/2012/02/saint-martins-islandbangladesh.html). Solar energy, the sun's rays that reach the earth and is converted to energy through solar panels (Ambia et al. 2010). However, the utilization factor is considered only about 25%-30% of sunlight radiation for Photovoltaic (PV) module (http://en.wikipedia.org/wiki/Photovoltaics). Thus, energy output of the PV using the available solar radiation can be calculated in Watts according to following equation: P A. x 2 B. x C
(1) Where, x-solar radiation, P-power generation, and A, B, C are constants, which can be delivered from measured data. The clearness index is a measure of the cleanness of the atmosphere has 3
Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 an average value of 0.4805 for Saint Martin. Figure 3 shows the clearness index and daily radiation for Saint Martin. The annual average solar insolation in Saint Martin is 4.857kWh/m2/day. Therefore, the island receives approximately an energy equivalent to 38.856 GWh/day. Figure 3: Clearness index & daily radiation for a year
Solar intensity of sun varies throughout the day at different locations. At noon when the sun is overhead, solar intensity is considered as 1000 W/m 2. Thus, considering 10 hours of daylight about 3.5kWh energy can be received as shown in Figure 4. Therefore, the solar insolation of Saint Martin can produce enough electric power to meet the power demand of this Island. Figure 4: Average sunny hours in a day
4. Wind Energy Analysis in Saint Martin Wind is another renewable energy source in Saint Martin which can also be used for electricity generation. Wind turbine can be used in conjunction with the solar energy to produce electricity. So that an efficient nano hybrid power station can be established in Saint Martin. We analyzed the wind characteristics in Saint Martin for this purpose.
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Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 Figure 5: Wind speed characteristic at Saint Martin for 12 months duration
Months: 1-Jan; 2-Feb; 3- Mar; 4- April; 5-May; 6- June; 7- July; 8- Aug; 9- Sep; 10-Oct; 11- Nov; 12-Dec. It is found that the average wind speed at Saint Martin is about 4.89 m/s through the year (Hossain & Yasmin 2012) with 30m hub height. If we increase the hub height then it is possible to get more wind speed. It is clear from Figure 5 that the maximum wind speed is found during June-August in a year. So the power generation will be increased during this time period. It is important to note that this is the hot summer time in Bangladesh so normally the electricity demand increased during this period and we can meet this requirement naturally.
5. Design of Proposed Hybrid System Here we propose a hybrid nano renewable energy based power station i.e. solar & wind energy based. Though the average wind speed at Saint Martin is not sufficient but wind energy in conjunction with solar energy can serve as an efficient renewable energy based power station. Estimated system can be design is shown in Table 2.
Energy Source
Table 2: Proposed Hybrid System Expected Unit Number Output Capacity Capacity of Units (Average)
Solar Panel
72 KW
240 Watt
300
60 KW
Wind Turbine
80 KW
800 Watt
100
40 KW
Total
100 KW
The start-up wind speed cut in wind speed and rated wind speed for the wind turbine have been considered about 1.5 m/s, 2 m/s and 12 m/s respectively (http://infinitewindpower.en.madeinchina.com/product/ibpQefrusyYD/China-Max-1200W-Home-Wind-Turbine-Generator System.html). At Saint Martin the average wind speed is 4.89 m/s, so we can get on an average 400 Watt output from each of the wind turbine. But if we get more wind speed depending on the weather condition the energy generation can be higher. The solar panels & batteries are locally available. Proposed system is shown in Figure 6.
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Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 Figure 6: Proposed hybrid system
Solar Panel W
Tr ansmission Line
in dT ur bi ne
Ir r igat ion
Sw it ch
Ener gy Conver sion
Hybr id Nano-Pow er St at ion Dist r ibut ion
6. Expected Outcome If it is possible to implement the above system in Saint Martin then and if we can use renewable energy compatible light, fan etc. it is possible to provide electricity to the residents of Saint Martin and tourists’ hotel & restaurants. This electricity can compensate their basic electricity need. That means they can use at least one light and one fan for each family. Normally a family in Saint Martin can be served with 120 Watt electric power by using this proposed system. This 120 watt power can be used to run at least 2 lights and 2 fans for each family. If energy efficient light and fan is used then it is also possible to support more lights and fans per family. Generated and consumed power estimation is shown in Table 3.
Number of Families 778
Table 3: Outcome of the Proposed System *Basic Power Total Required Estimated Consumption/Family Power Generated Power 120 Watt
93.36 KW
100 KW
*renewable energy compatible 2 lights, 2 fans
7. Conclusion A new hybrid renewable energy based nano power station is proposed. The analysis was done using the data provided by different research activities. The main advantage of this nano-power station is that it can be implemented locally using the natural resources i.e. solar & wind energy. Moreover it is one time investment and required a little maintenance. Using this type of hybrid system basic electricity requirement for a remote isolated island can be served effectively and efficiently. 6
Proceedings of 4th Global Engineering, Science and Technology Conference 27-28 December, 2013, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-43-6 Reference A Pre-Feasibility Study Report (2010). ‘‘Solar-Wind-Diesel Hybrid for Power Generation in Small Towns and Villages’’ Prepared by the PREGA National Technical Experts from Bangladesh Centre for Advanced studies, Tech Rep. A publication of Spilling Energy System (2008). "Gas Expansion Power Plants with Modular System Gas Expanders" 27, 262-265. Ambia, M. N., Islam, M. K., Shoeb, M. A., Maruf, M. N. I., Mohsin, A.S.M., (2010). An Analysis & Design on Micro Generation of A Domestic Solar-Wind Hybrid Energy System for Rural & Remote Areas-Perspective Bangladesh, International Conference on Mechanical and Electronics Engineering (ICMEE), pp. 107-110, 2010. Ashok, S. (2007). Optimized model for community-based hybrid energy system, Renewable Energy, Vol. 32, pp. 1155-1164, June 2007. Bangladesh Energy Crisis: Soul Searching, Energy Bangladesh, (2011, March). URL:http://www.energybangla.com/index.php?mod=article& cat=Something to Say article=2051. Bangladesh Power Development Board (BPDB), http://www.bpdb.gov.bd. (Accessed on January, 2013). Halder, P. K., Joardder, M. U. H., Beg, M. R. A., Paul, N., & Ullah, I. (2012). Utilization of bio-oil for cooking and lighting. Advances in Mechanical Engineering. Haque, M. E. (2011). Bangladesh’s Power Sector: Investment Opportunities, Ministry of Power, Energy & Mineral Resources, Bangladesh, Presented in London, Mar. 2011. Hossain, M. A., & Yasmin, S. (2012). Extraction of Wind Power at different Windy Locations in Bangladesh, Proceedings of 7th IEEE International Conference on Electrical & Computer Engineering (ICECE), December 20-22, 2012, Dhaka, Bangladesh, pp.763-766. http://en.wikipedia.org/wiki/Wind_power. (Accessed on Jan, 2013). http://icwow.blogspot.com/2012/02/saint-martins-island-bangladesh.html. (Accessed on Jan, 2013). http://infinitewindpower.en.made-in-china.com/product/ibpQefrusyYD/China-Max-1200W-HomeWind-Turbine-Generator-System.html (Accessed on July, 2013). Islam MN. Energy Context in Bangladesh (2001). In: Islam AKM, Infield DG, editors. Photovoltaic technology for Bangladesh. Dhaka, Bangladesh and UK: Bangladesh University of Engineering and Technology and Loughborough University; p. 1–18. Kaldellis J. K. et al. (2006). Sizing a Hybrid Wind-Diesel Stand-Alone System on the Basis of Minimum Long-Term Electricity Production Cost, Applied Energy, Vol. 83, pp. 1384-1403. Wikipedia on Photovoltaic. Available at: http://en.wikipedia.org/wiki/Photovoltaics. (Accessed on Jan, 2013)
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